Method for improving weight qualification rate of in-furnace plate blank

Abstract

The invention discloses a method for improving the weight qualification rate of in-furnace plate blanks. The method comprises the following steps: (1) measuring and calculating a weight difference influence factor K of section blanks with different thicknesses by utilizing an actual weighing weight difference and stokehold measurement data; (2) a weight difference measurement formula C = K * (Lmeasured Bmeasured / L0B0)-1 is programmed in a stokehole plate blank measurement system program, Lmeasured is measured length, Bmeasured is measured width, L0 is theoretical length, B0 is theoretical width, and the weight difference is automatically calculated after the plate blank is subjected to stokehole length measurement and width measurement; (3) system setting: when-0.3% < = C < = 3%, the plate blank automatically passes to the front of a furnace to wait for steel loading, under other conditions, the plate blank automatically stops after passing through a length measuring device, is lifted down before being opened back to a width measuring device, and meanwhile, a blank worker is notified to change the theoretical size of the system; and (4) correcting stokehole width measurement and length measurement data once a month. The method has the advantages that the weight difference qualification rate of the in-furnace plate blanks is increased, the rolling size non-planning caused by insufficient plate blank weight is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of steel, and in particular relates to a method for improving the weight qualification rate of furnace-entering slabs. Background Art

[0002] The weight of the ingot directly affects the size of the rolled steel plate. Usually, a weighing device is added in front of the furnace to weigh the ingot piece by piece, but this method undoubtedly reduces production efficiency. Since the actual length, width and thickness are measured in front of the furnace and the weight of the slab is calculated piece by piece, the calculation data is inaccurate due to the irregular shape of the ingot, such as an inverted trapezoidal shape, that is, the width is wide at the top and narrow at the bottom, and the large chamfered corners of the crystallizer are not right angles. At present, the steel rolling mill mainly restricts the weight of the slab by sampling and weighing, and the continuous casting machine adjusts the weight difference by length and width measurement, but it still cannot effectively avoid the batch width or length short gauge caused by insufficient slab weight. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of low efficiency and low accuracy in the existing ingot weight measurement, and to provide a method for improving the qualified rate of the weight of the slabs entering the furnace, which can improve the qualified rate of the weight difference of the slabs entering the furnace, reduce the unplanned rolling size caused by insufficient slab weight, improve the accuracy of the ingot weight measurement data, and reduce production costs.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A method for improving the qualified weight rate of slabs entering a furnace, the specific steps are as follows: (1) Using the actual weighing difference and the measurement data before the furnace, calculate the weighing difference influence factor K of the billet with different thickness sections and input it into the system; (2) The weight difference determination formula C = K* (L 测 B 测 / L0B0)-1, where L 测 is the measured length, B 测 To measure the width, L0 is the theoretical length, B0 is the theoretical width, and the slab is automatically calculated after the length and width are measured in front of the furnace; (3) System setting: when -0.3%≤C≤3%, the slab automatically passes to the furnace and waits for steel loading. In other cases, the slab automatically stops after passing the length measuring device, and is returned to the width measuring device and hoisted down. At the same time, the slab worker is notified to modify the theoretical size of the system. (4) The width and length measurement data in front of the furnace should be calibrated once a month to ensure the accuracy of the measurement data.

[0005] Furthermore, in step (1), the weight difference is defined as C=(W-W0) / W0, wherein W is the actual weighing weight of the slab, W0 is the theoretical weight of the slab, and W=ρHLB, wherein ρ is the density, H is the thickness of the slab, L is the length of the slab, and B is the width of the slab. Then, C=(W-W0) / W0=K*(BL / B0L0)-1. Since the shapes of the sections with the same thickness of the same casting machine are basically the same, the weight difference influencing factor K under sections with different thicknesses can be calculated by combining the length and width measurement data in front of the furnace with the actual weighing data.

[0006] Furthermore, in step (1), for a group of slabs of the same material and the same thickness, the weight difference influence factor K' corresponding to each slab is calculated one by one, and then the weight difference influence factor K' of this group K1', K2', K3'...K n 'Take the average value to get the correction coefficient K0.

[0007] Furthermore, in the step (3), when C < -0.003 or C > 0.03, the slab automatically stops after passing the length measuring device.

[0008] Compared with the prior art, the advantages of the technical solution of the present invention are: (1) The present invention can measure the weight difference of slabs piece by piece, control the weight difference of slabs entering the furnace in advance, and reduce the size non-planning caused by insufficient slab weight; (2) The present invention is not affected by the temperature of the slab entering the furnace, and effectively avoids the unplanned batch size caused by insufficient slab weight of hot-charged slabs; (3) The method of the present invention is simple and easy to operate, which improves the measurement efficiency and the qualified rate of the weight of the slabs entering the furnace, thereby ensuring the quality of the slabs. DETAILED DESCRIPTION Example

[0009] In order to make the present invention more clear, a method for improving the weight qualification rate of slabs entering the furnace according to the present invention is further described below. The specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0010] This embodiment takes the 260*2570mm section of the No. 3 continuous casting machine as an example, and the method for improving the qualified rate of the weight of the slab entering the furnace is carried out according to the following steps, which are characterized in that: (1) Calculate the correction coefficient K0 using the actual weighing difference and the furnace measurement data, as shown in the following table:

[0011] (2) From the above steps, we can get K0 as 0.9925. Therefore, the weight difference determination formula C = 0.9925*(L 测 B 测 / L0B0)-1, where L测 is the measured length, B 测 To measure the width, L0 is the theoretical length, B0 is the theoretical width, and the slab is automatically calculated after the length and width are measured in front of the furnace; (3) System setting: when -0.003≤C≤0.03, the slab automatically passes to the furnace to wait for steel loading; when C<-0.003 or C>0.03, the slab automatically stops after passing the length measuring device; (4) Taking slab No. 2430781204 as an example, its three-level dimensions are 260*2570*3864mm, the measured width is 2575mm, and the measured length is 3871mm. The slab stops automatically after passing through the length measuring device, and the interface displays the scale difference of -0.0038, with an alarm prompting "Insufficient difference, loading into the furnace is prohibited"; (5) The slab is opened back and hoisted in front of the width measuring device, and the slab worker is informed to change the length of the slab from 3864mm to 3850mm. After the modification, the weight difference is -0.0001, which meets the requirements and waits for the order to be placed again for production.

[0012] The present invention can quickly calculate the weight deviation of irregular slabs through the length and width measurement data in front of the furnace, meet the requirements of normal furnace loading and production, and control the falling of slabs with insufficient weight, thereby improving the weight qualification rate of slabs entering the furnace and reducing size non-planning. The present invention can be widely used for irregular right-angle billets or arc chamfered billets.

[0013] After the method of the present invention is implemented, the non-planned size rate is reduced from 0.18% to 0.11%, the annual output is 1.6 million tons, the price difference between genuine and non-planned tons of steel is 500 yuan / ton, and the annual benefit N is calculated as: N=1.6 million tons / year*(0.18%-0.11%)*500 yuan / ton=560,000 yuan / year.

[0014] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A method for improving the weight qualification rate of slabs entering a furnace, characterized in that: (1) Using the actual weighing difference and the furnace measurement data, calculate the weighing difference influence factor K of the billet with different thickness sections and input it into the system; (2) The weight difference determination formula C = K* (L 测 B 测 / L0B0)-1, where L 测 is the measured length, B 测 To measure the width, L0 is the theoretical length, B0 is the theoretical width, and the slab is automatically calculated after the length and width are measured in front of the furnace; (3) System setting: when -0.3%≤C≤3%, the slab automatically passes to the furnace and waits for steel loading. In other cases, the slab automatically stops after passing the length measuring device, and is returned to the width measuring device and hoisted down. At the same time, the slab worker is notified to modify the theoretical size of the system. (4) The width and length measurement data in front of the furnace should be calibrated once a month to ensure the accuracy of the measurement data.

2. The method for improving the weight qualification rate of slabs entering the furnace according to claim 1, characterized in that: In the step (1), the weight difference is defined as C=(W-W0) / W0, where W is the actual weighing weight of the slab, W0 is the theoretical weight of the slab, and W=ρHLB, where ρ is the density, H is the slab thickness, L is the slab length, and B is the slab width. Then C=(W-W0) / W0=K*(BL / B0L0)-1. Since the shapes of the sections with the same thickness of the same casting machine are basically the same, the weight difference influence factor K under sections with different thicknesses can be calculated by combining the length and width measurement data in front of the furnace with the actual weighing data.

3. The method for improving the weight qualification rate of slabs entering the furnace according to claim 1 or 2, characterized in that: In the step (1), for a group of slabs of the same material and the same thickness, the weight difference influence factor K' corresponding to each slab is calculated one by one, and then the weight difference influence factor K1', K2', K3'...K n 'Take the average value to get the correction coefficient K0.

4. The method for improving the weight qualification rate of slabs entering the furnace according to claim 1 or 2, characterized in that: In the step (3), when C < -0.003 or C > 0.03, the slab automatically stops after passing the length measuring device.

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